scholarly journals Electrostatic Zipping Actuators—Analysis of the Pull-In Effect Depending on the Geometry Parameters

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8355
Author(s):  
Jacek Szkopek ◽  
Grzegorz Redlarski ◽  
Arkadiusz Żak

Continuous work on a new generation of actuators, referred to as artificial muscles, resulted in the initiation of work on electrostatic zipping actuators, the concept of which is derived from micro electro-mechanical devices. Despite partial knowledge of their basic operating parameters, a question remains whether electrostatic zipping actuators are able to meet the expectations in the context of generated forces and control possibilities. In order to get closer to the answer to this question, the authors of this work created a solution method using FEM, which allowed them to conduct a series of concentric contraction tests of the desired solution. In addition to the basic features of the actuators tested, such as their length, thickness and width, for the first time the size of the weld surface, to which the loading force was applied, was taken into account. The results of the investigations show the possibility of adjusting the supply voltage range to the application requirements, but most importantly, they present the variability of the pull-in strain parameter. In extreme configurations, its value increases from ~10% to ~26%. The results obtained emphasize the need for further analysis of electrostatic zipping actuators using FEM. It will make it possible to precisely define the characteristics of this technology as well as its limits. These activities will provide the ultimate answer to the potential of electrostatic zipping actuators as artificial muscles.

2007 ◽  
Vol 19 (6) ◽  
pp. 619-628 ◽  
Author(s):  
Toshiro Noritsugu ◽  
◽  
Daisuke Sasaki ◽  
Masafumi Kameda ◽  
Atsushi Fukunaga ◽  
...  

As society ages and birth rates fall, the dropping number of caregivers for an increasingly elderly population is expected to become a serious problem, raising the need for devices to assist those having difficulty in leading independent lives. These devices must be used near or directly on their users, making safety and user-friendliness equally important. This raises the need for safe, user-friendly actuators that are compact, lightweight, and appropriately soft. The pneumatic rubber artificial muscle meets this requirement. We developed a wearable power assist device that aids people in standing and uses the McKibben pneumatic rubber artificial muscle. We discuss its structure, basic features, and control. We also present an example of its application to rehabilitation.


Author(s):  
Sunil Kumar Rajendran ◽  
Qi Wei ◽  
Feitian Zhang

Deficit of the extraocular muscle is known as a key cause of ocular motility disorders that affect eye movement and complicate daily activities of millions of people in the US. A physical model mimicking the biomechanics of the oculomotor plant can improve the understanding of functionality and control of extraocular muscles and provide a tool for researchers to gain insights into binocular misalignment. This paper will present, for the first time, the design and development of a robotic eye system driven by antagonistic super coiled polymer (SCP) based artificial muscles and the motion control design by leveraging machine learning techniques. The dynamic model of the robotic eye will be presented. Deep reinforcement learning is used for control design of the robotic eye system, demonstrated by simulation of one-dimensional foveation control.


Author(s):  
S.J. Krause ◽  
W.W. Adams

Over the past decade low voltage scanning electron microscopy (LVSEM) of polymers has evolved from an interesting curiosity to a powerful analytical technique. This development has been driven by improved instrumentation and in particular, reliable field emission gun (FEG) SEMs. The usefulness of LVSEM has also grown because of an improved theoretical and experimental understanding of sample-beam interactions and by advances in sample preparation and operating techniques. This paper will review progress in polymer LVSEM and present recent results and developments in the field.In the early 1980s a new generation of SEMs produced beam currents that were sufficient to allow imaging at low voltages from 5keV to 0.5 keV. Thus, for the first time, it became possible to routinely image uncoated polymers at voltages below their negative charging threshold, the "second crossover", E2 (Fig. 1). LVSEM also improved contrast and reduced beam damage in sputter metal coated polymers. Unfortunately, resolution was limited to a few tenths of a micron due to the low brightness and chromatic aberration of thermal electron emission sources.


2002 ◽  
Vol 16 (2) ◽  
pp. 109-124 ◽  
Author(s):  
William E. Shafer ◽  
D. Jordan Lowe ◽  
Timothy J. Fogarty

The current trend toward corporate acquisitions of CPA firms poses potential threats to the autonomy and ethical standards of public accounting professionals. This recent consolidation movement suggests that for the first time a significant number of public accounting professionals are subject to the supervision and control of nonprofessionals. In addition to acknowledging the potential threats to auditor independence and objectivity, this paper suggests that these new organizational arrangements for the provision of public accounting services have other negative effects on professionalism and ethics such as desensitizing CPAs to traditional professional values, and subverting professional institutions to the goals of corporate employers. This paper develops a framework that identifies several specific research questions related to the effects of corporate ownership on professionalism and ethics in public accounting.


Author(s):  
Iain A. Anderson ◽  
Benjamin M. O’Brien

Mechanical devices that include home appliances, automobiles, and airplanes are typically driven by electric motors or combustion engines through gearboxes and other linkages. Airplane wings, for example, have hinged control surfaces such as ailerons. Now imagine a wing that has no hinged control surfaces or linkages but that instead bends or warps to assume an appropriate shape, like the wing of a bird. Such a device could be enabled using an electro-active polymer technology based on electronic artificial muscles. Artificial muscles act directly on a structure, like our leg muscles that are attached by tendon to our bones and that through phased contraction enable us to walk. Sensory feedback from our muscles enables proprioceptive control. So, for artificial muscles to be used appropriately we need to pay attention not only to mechanisms for muscle actuation but also to how we can incorporate self-sensing feedback for the control of position.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1762
Author(s):  
Artur Maciej ◽  
Natalia Łatanik ◽  
Maciej Sowa ◽  
Izabela Matuła ◽  
Wojciech Simka

One method of creating a brass coating is through electrodeposition, which is most often completed in cyanide galvanic baths. Due to their toxicity, many investigations focused on the development of more environmentally friendly alternatives. The purpose of the study was to explore a new generation of non-aqueous cyanide-free baths based on 1-ethyl-3-methylimidazolium acetate ionic liquids. The study involved the formation of copper, zinc, and brass coatings. The influence of the bath composition, cathodic current density, and temperature was determined. The obtained coatings were characterized in terms of their morphology, chemical composition, phase composition, roughness, and corrosion resistance. It was found that the structure of the obtained coatings is strongly dependent on the process parameters. The three main structure types observed were as follows: fine-grained, porous, and olive-like. To the best knowledge of the authors, it is the first time the olive-like structure was observed in the case of an electrodeposited coating. The Cu-Zn coatings consisted of 19–96 at. % copper and exhibited relatively good corrosion resistance. A significant improvement of corrosion properties was found in the case of copper and brass coatings with the olive-like structure.


2021 ◽  
Vol 137 (2) ◽  
pp. 451-476
Author(s):  
Imelda Chaxiraxi Díaz Cabrera ◽  
Carolina Jorge Trujillo

Abstract Manuel Alvar published the only linguistic work known on Spanish from the island of La Graciosa (Canary Islands) in 1965, focused on the town of Caleta del Sebo, to document, in the field of Linguistic geography, the ALEICan (Linguistic and ethnographic atlas of the Canary Islands [1975–1978]). Alvar’s studies used to cover the lexical, grammatical (morphology and syntax) and phonetic levels of the segmental type, but he did not consider prosodic aspects of speech which would later be incorporated into a new generation of atlases, which would go from paper format to multimedia. As the main exponent, the AMPER project (Atlas Multimédia Prosodique de l’Espace Roman) was created in 2001 and, within its framework, we intend to describe the melodic characteristics of a group of sentences emitted by a man and a woman from Caleta del Sebo, completing thus the study started by Alvar fifty-five years ago. In this way, the results will show for the first time if there is a prosodic proximity between the eighth island and the seven main islands, which have been widely described in previous works both in formal and in informal speech.


2006 ◽  
Vol 13 (6) ◽  
pp. 648-654 ◽  
Author(s):  
W. R. Waters ◽  
M. V. Palmer ◽  
T. C. Thacker ◽  
J. P. Bannantine ◽  
H. M. Vordermeier ◽  
...  

ABSTRACT Bovine tuberculosis persists as a costly zoonotic disease in numerous countries despite extensive eradication and control efforts. Sequential serum samples obtained from Mycobacterium bovis-infected cattle were evaluated for seroreactivity to mycobacterial antigens. Animals received M. bovis by aerosol, intratonsil, intranasal, or intratracheal inoculation. Assays included the multiantigen print immunoassay for determination of antigen recognition patterns, immunoblot analysis for sensitive kinetic studies, and the VetTB STAT-PAK test, a novel, rapid test based on lateral-flow technology. Responses to MPB83 were detected for all M. bovis-infected animals regardless of the route or strain of M. bovis used for inoculation. Other less commonly recognized antigens included ESAT-6, CFP-10, and MPB70. Responses to MPB83 were detectable as early as 4 weeks after inoculation, were boosted upon injection of purified protein derivatives for skin testing, and persisted throughout the course of each of the four challenge studies. MPB83-specific immunoglobulin M (IgM) was detected prior to MPB83-specific IgG detection; however, early IgM responses rapidly waned, suggesting a benefit of tests that detect both IgM- and IgG-specific antibodies. The VetTB STAT-PAK test detected responses in sera from 60% (15/25) of the animals by 7 weeks after challenge and detected responses in 96% (24/25) of the animals by 18 weeks. These findings demonstrate the potential for new-generation antibody-based tests for the early detection of M. bovis infection in cattle.


2015 ◽  
Vol 785 ◽  
pp. 576-580 ◽  
Author(s):  
Liaw Geok Pheng ◽  
Rosnani Affandi ◽  
Mohd Ruddin Ab Ghani ◽  
Chin Kim Gan ◽  
Jano Zanariah

Solar energy is one of the more attractive renewable energy sources that can be used as an input energy source for heat engines. In fact, any heat energy sources can be used with the Stirling engine. Stirling engines are mechanical devices working theoretically on the Stirling cycle, or its modifications, in which compressible fluids, such as air, hydrogen, helium, nitrogen or even vapors, are used as working fluids. When comparing with the internal combustion engine, the Stirling engine offers possibility for having high efficiency engine with less exhaust emissions. However, this paper analyzes the basic background of Stirling engine and reviews its existing literature pertaining to dynamic model and control system for parabolic dish-stirling (PD) system.


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